I lost the key to my Kryptonite U-lock and my bike is unridable until I can break it free. Does anyone know how I can break open one of these ? I'm thinking a mallet and some brute force or do I need a locksmith?

All you need is a pal who is a mechanic or go to tool rental and get a portable grinder with a cut off wheel, safety glasses suggested. If you walked up to my door with it I would cut it off in 30 seconds for you.

Utah**********?

Unless, you could get them a number and buy a new key from the factory....

Bike theifs usually insert a scissor jack or a very long lever.

A hacksaw or a grinder with a cutoff wheel NOT a grinding wheel. If you can get a hold of a portaband use that,makes short work of cutting very thick metal,a cutting torch,a rebar cutter or,what the hell, high explosives!!!!! LOL Just kidding the portaband would be the best,no sparks like the grinder and no slag like the torch. I'm a Sheetmetal worker and have lots of experience with all types of metal,if you wanna do it on the cheap hacksaw.

I would hope it doesn't give up that easy. I would hope it would be like trying to hacksaw through hardened tool steel.

Be interesting to find out if it gives up easily though wouldn't it?

-Roger

well the problem is it's locked to a bike rack. I thought about driving up to it and using a dremel with a cutting wheel. Its an older krypto lock, the metal is about 3/4 or so thick.

Make sure you pick the nicest bike.

You'll need a tungsten carbide hacksaw blade if you go the hacksaw route...the hardened steel of a U-Lock requires it. Milwaukee sells a good one through amazon.com if you can't find one locally. You still have to eat your wheaties, though, as getting through the U-Lock still takes ~30 minutes of sawing.

Got an old abandoned Schwinn breeze this way. Overhauled it, built up a new wheelset for it, and now it's my girlfriend's commuter.

Kryptonite U-locks are all made of hardened steel. Fastest and easiest way is with a portable angle grinder with a cutoff wheel.

You said it's an older one? Does it have a round key? If so, there might be a quieter way:
https://www.youtube.com/watch?v=t8XxcOj3Seo

Thanks for the link, TM -- I had heard about that issue but hadn't seen the demonstration! There was an interesting Slate article a few years ago where the author went at various bike locks with hand tools to see how they fared.

+1 on a hacksaw won't do it. Either a grinder or a Dremel with a cut-off wheel will. Drape some wet cloths over the bike to keep the sparks from damaging the paint.

The jack, etc, approach is likely to damage the bike, particularly if it slips.

A dremel is going to take an awful long time to get through 3/4" hardened steel. Harbor Freight sells angle grinders for $19.99, sometimes less depending on sale dates. I've used one, in combination with a power inverter and a 50' extension cord from our van to cut off locks for a friend who broke his keys in the lock being an idiot. Its still a longer process than cutting a cable lock, and will likely draw some attention (though I've never been questioned by anything more than a curious eye when doing this) so be prepared to explain what's going on.

If the U lock is one of the older variety with a cylindrical key, you're in luck.
Since about 2000, it's been well known that you can pick it with a ball point
pen barrel. (Biro)

After I found this out, I was able to open my motorcycle disc lock in about
15 seconds.

https://www.wired.com/culture/lifesty.../2004/09/64987


If you have one of the new & improved U locks, dig around for the paperwork
from when you bought it. If you can come up with the lock's serial number or
a key number, Kryptonite will get you a replacement key, no problem (but not
no cost...)

For some methods demonstrated: https://www.youtube.com/watch?v=5TNTq3nhuh0

fire wrench...

I have cut a u lock with a grinder. Buy a grinder and a metal cutting blade you will have the lock cut in 30 secs.

That looks awesome! Can you mail me one?

There is the explanation for bike theft in a nutshell, right? Unless a law enforcement type who cares happens on the scene, most people won't bat an eye if someone who looks like they are doing something they are supposed to be doing is cutting locks off of a bike rack. If it's in broad daylight and you don't look nervous, you can steal almost anything on a public way. For full effect, have a buddy stand around watching while drinking a cup of coffee, just like the pros do it ;-)

To avoid any problems you might want to notify the local cops in advance. Easier than explaining later if they get curious as to whose bike it really is.

Hello? NYPD? I'm just calling in advance to notify you that I will be sitting at 136th and 73rd with a hacksaw sawing at a bike lock from 2:00 to 3:00.There's nothing to be worried about and you can just drive right on past me. Have a good day!

36" or bigger bolt cutters.

That's pretty much it. But you might want to let them know the make, model and serial no. too.

However, give it's NYC, the cops will probably drive right by even if you don't notify them in advance.

Oh please. Do this in an urban/downtown ish environment and you can be getting ***** on the corner of front and university and nobody would bat an eye.

Seriously.

Nobody cares or want to care.